RS232 Serial not communicating

Hello to all!

I've spend the last month trying to troubleshoot why my arduino board is not sending serial commands over RS232. The device is a card dispenser that uses RS232 to control it. I have a arduino Uno and a linksprit RS232 shield with a MAX3232 chip. Starting simple I'm just trying to code the Eject Front command shown below under command structure. The device receives ASCII codes. According to the device manual it reads:

Communication Protocol:
Baud rate(BPS): Can be set by controller(Default at 9600BPS)
Communicate Mode: Asynchronous communication
Transmit mode: Half duplex
Data frames structure: Start bit: 1bit
Data bit:8bits
A Check Bit: No
Stop Bit:1bit

Command Structure:
Eject Front command
15FC
: 0 2 H , Frame start
: 0 3 H , Frame end
: ? O ? O ? O ? O ? ,Block checkout
‘O’ : Means a character’s ASCII code
‘X’ : Means a character’s ASCII code

I've written the code below in HEX only because I'm confused on how to send the start and end frame in ASCII. Also because I listened to the communication between the device and PC and matched the HEX commands but the code send should be ASCII according to the manual.

#include <SoftwareSerial.h>

SoftwareSerial deviceSerial(6, 7); // RX, TX

void ejectFront();

void setup() {
Serial.begin(9600);
deviceSerial.begin(9600);
}

void loop() {

ejectFront();
}

void ejectFront() {
deviceSerial.write(0x02);
deviceSerial.write(0x31);
deviceSerial.write(0x35);
deviceSerial.write(0x46);
deviceSerial.write(0x43);
deviceSerial.write(0x30);
deviceSerial.write(0x03);
deviceSerial.write(0x30);
}

Thank you for taking your time to read this.

Hi, welcome to the forum.

Could you give links to the RS-232 shield and the card dispenser ?

This shield ?
http://linksprite.com/wiki/index.php5?title=RS232_Shield_V2_for_Arduino

The serial communication with 9600, 8N1 is the default. That is okay.
Did you use jumpers ? how ?
Can you test the shield with a computer with an RS-232 port ? I would like to be sure that the shield is working before trying to communicate with the card dispenser.

The protocol is confusing. I don't understand it. The code is your sketch is not "15FCBCC". Because that is 7 bytes and you transmit 8 bytes, and how do you know what the checksum should be ?

The checksum can be an XOR or ADD checkum. Without the right value for the checksum, the device would ignore the data.

Is there a command to make the device show the status ?